class in UnityEngine.UIElements
/
Inherits from:UIElements.PointerEventBase_1
/
Implemented in:UnityEngine.UIElementsModule
Sends when a pointer is pressed inside a visual element.
In a runtime UI, a PointerDownEvent is sent each time a user touches the screen or presses a mouse button.
In an Editor UI, a PointerDownEvent is sent when a user initially touches the screen or presses a mouse button. However,
If the user presses additional mouse buttons (right or middle) without releasing the initial one, the PointerMoveEvents is
sent not the PointerDownEvent. Releasing all mouse buttons and pressing a mouse button again sends a new PointerDownEvent.
A PointerDownEvent follows the default pointer event propagation path. It trickles down, bubbles up,
and is cancellable.
Disabled elements don't receive this event.
For information about how the PointerDownEvent relates to other pointer events, refer to PointerEventBase<T0>
and Pointer events.
Additional resources: PointerMoveEvent, PointerUpEvent, PointerCancelEvent
// This example creates a ClickDetector class to detect a click sequence.
namespace UnityEngine.UIElements
{
public class ClickDetector : VisualElement
{
public ClickDetector()
{
RegisterCallback<PointerDownEvent>(ProcessEvent);
RegisterCallback<PointerMoveEvent>(ProcessEvent);
RegisterCallback<PointerUpEvent>(ProcessEvent);
}
private void ProcessEvent<TEvent>(PointerEventBase<TEvent> evt)
where TEvent : PointerEventBase<TEvent>, new()
{
if (evt.eventTypeId == PointerDownEvent.TypeId() && evt.button == 0)
{
StartClickTracking(evt);
}
else if (evt.eventTypeId == PointerMoveEvent.TypeId())
{
// Button 1 was pressed while another button was already pressed.
if (evt.button == 0 && (evt.pressedButtons & 1) == 1)
{
StartClickTracking(evt);
}
// Button 1 is released while another button is still pressed.
else if (evt.button == 0 && (evt.pressedButtons & 1) == 0)
{
SendClickEvent(evt);
}
// Pointer movement detected or button state changed.
else
{
UpdateClickStatus(evt);
}
}
else if (evt.eventTypeId == PointerUpEvent.TypeId() && evt.button == 0)
{
SendClickEvent(evt);
}
}
private void StartClickTracking(IPointerEvent evt) { Debug.Log("Starting click sequence"); }
private void UpdateClickStatus(IPointerEvent evt) { Debug.Log("Tracking"); }
private void SendClickEvent(IPointerEvent evt) { Debug.Log("Completed click"); }
}
}
| PointerDownEvent | Constructor. Avoid creating new event instances. Instead, use GetPooled() to get an instance from a pool of reusable event instances. |
| Init | Resets the event members to their initial values. |
| bubbles | Returns whether this event type bubbles up in the event propagation path. |
| currentTarget | The current target of the event. This is the VisualElement, in the propagation path, for which event handlers are currently being executed. |
| dispatch | Indicates whether the event is being dispatched to a visual element. An event cannot be redispatched while it being dispatched. If you need to recursively dispatch an event, it is recommended that you use a copy of the event. |
| eventTypeId | Retrieves the type ID for this event instance. |
| imguiEvent | The IMGUIEvent at the source of this event. The source can be null since not all events are generated by IMGUI. |
| isDefaultPrevented | Returns true if the default actions should not be executed for this event. |
| isImmediatePropagationStopped | Indicates whether StopImmediatePropagation() was called for this event. |
| isPropagationStopped | Whether StopPropagation() was called for this event. |
| originalMousePosition | The original mouse position of the IMGUI event, before it is transformed to the current target local coordinates. |
| pooled | Whether the event is allocated from a pool of events. |
| propagationPhase | The current propagation phase for this event. |
| target | The target visual element that received this event. Unlike currentTarget, this target does not change when the event is sent to other elements along the propagation path. |
| timestamp | The time when the event was created, in milliseconds. |
| tricklesDown | Returns whether this event is sent down the event propagation path during the TrickleDown phase. |
| eventTypeId | Retrieves the type ID for this event instance. |
| actionKey | Gets a boolean value that indicates whether the platform-specific action key is pressed. True means the action key is pressed. False means it isn't. |
| altitudeAngle | Gets the angle of the stylus relative to the surface, in radians |
| altKey | Gets a boolean value that indicates whether the Alt key is pressed. True means the Alt key is pressed. False means it isn't. |
| azimuthAngle | Gets the angle of the stylus relative to the x-axis, in radians. |
| button | Gets a value that indicates which mouse button was pressed: 0 is the left button, 1 is the right button, 2 is the middle button. |
| clickCount | Gets the number of times the button was pressed. |
| commandKey | Gets a boolean value that indicates whether the Windows/Cmd key is pressed. True means the Windows/Cmd key is pressed. False means it isn't. |
| ctrlKey | Gets a boolean value that indicates whether the Ctrl key is pressed. True means the Ctrl key is pressed. False means it isn't. |
| currentTarget | Gets the current target of the event. |
| deltaPosition | Gets the difference between the pointer's position during the previous mouse event and its position during the current mouse event. |
| deltaTime | Gets the amount of time that has elapsed since the last recorded change in pointer values, in seconds. |
| isPrimary | Gets a boolean value that indicates whether the pointer is a primary pointer. True means the pointer is a primary pointer. False means it isn't. |
| localPosition | Gets the pointer position in the current target's coordinate system. |
| modifiers | Gets flags that indicate whether modifier keys (Alt, Ctrl, Shift, Windows/Cmd) are pressed. |
| pointerId | Gets the identifier of the pointer that sent the event. |
| pointerType | Gets the type of pointer that created the event. |
| position | Gets the pointer position in the Screen or World coordinate system. |
| pressedButtons | Gets a bitmask that describes the buttons that are currently pressed. |
| pressure | Gets the amount of pressure currently applied by a touch. |
| radius | Gets an estimate of the radius of a touch. |
| radiusVariance | Gets the accuracy of the touch radius. |
| shiftKey | Gets a boolean value that indicates whether the Shift key is pressed. True means the Shift key is pressed. False means it isn't. |
| tangentialPressure | Gets the pressure applied to an additional pressure-sensitive control on the stylus. |
| twist | Gets the rotation of the stylus around its axis, in radians. |
| Dispose | Implementation of IDisposable. |
| PreventDefault | Indicates whether the default actions are prevented from being executed for this event. |
| StopImmediatePropagation | Immediately stops the propagation of the event. The event isn't sent to other elements along the propagation path. This method prevents other event handlers from executing on the current target. |
| StopPropagation | Stops propagating this event. The event is not sent to other elements along the propagation path. This method does not prevent other event handlers from executing on the current target. |
| Dispose | Implementation of IDispose. |
| PostDispatch | Allows subclasses to perform custom logic after the event has been dispatched. |
| PreDispatch | Allows subclasses to perform custom logic before the event is dispatched. |
| RegisterEventType | Registers an event class to the event type system. |
| GetPooled | Gets an event from the event pool. Use this function instead of creating new events. Events obtained using this method need to be released back to the pool. You can use Dispose() to release them. |
| TypeId | Retrieves the type ID for this event instance. |
| GetPooled | Gets an event from the event pool and initializes it with the given values. Use this function instead of creating new events. Events obtained using this method need to be released back to the pool. You can use Dispose() to release them. |